1. Field of the Invention
This invention relates to a logarithmic amplifier, and more particularly to a logarithmic amplifier employing a log-conversion element such as a semiconductor diode provided with means for temperature compensation of the output thereof.
2. Description of the Prior Art
In a logarithmic amplifier employing a log-conversion element such as a semiconductor diode, the temperature compensation should be made for various range of current since the temperature coefficient of the diode varies as the amount of current flowing therethrough varies. Therefore, in the conventional logarithmic amplifiers, one or more steps of amplifiers are added and the amplification factor of the amplifiers is temperature compensated over the wide range of current by use of a thermistor or the like. Such a logarithmic amplifier employing a thermistor cannot be made into a monolithic form of small size.